Can't Round Trip Instant using default serializers about nodatime.serialization

[jskeet]

You haven't shown settings, but I'm assuming that's the JsonSerializerSettings that's configured for Noda Time. You're passing that into DeserializeObject but not into SerializeObject.

Just change the second line to

var json = JsonConvert.SerializeObject(instantInAClass, settings);

and I'd expect it to be fine.

[thegreatco]

Doh! You're right. This was an admittedly rushed attempt at a repro for a problem I have in my code. I do provide the settings on both deserialize and serialize (checked in the debugger to see the converter is registered) but I can't get the instant to round trip. I'll update with more information in the morning.

[jskeet]

Okay, we'll leave the issue open for the moment. Good luck reproducing it. (Does it surface in the same way in your real code, or does it deserialize, but lose information?)

[thegreatco]

Ok, this is the error I get, using a sample program written in LINQPad.

void Main()
{
	try
	{
		var jsonSettings = new JsonSerializerSettings();
		jsonSettings.Converters.Add(NodaConverters.InstantConverter);

		var foo = new InstantTestClass() { Now = SystemClock.Instance.GetCurrentInstant() };
		var json = JsonConvert.SerializeObject(foo, jsonSettings);
		Console.WriteLine(json);
		var newJson = JsonConvert.DeserializeObject<InstantTestClass>(json, jsonSettings);
		Console.WriteLine(newJson);
	}
	catch(Exception ex)
	{
		Console.WriteLine(ex.ToString());
	}
}

// Define other methods and classes here
public class InstantTestClass
{
	public Instant Now {get;set;}
}

The output is

{"Now":"2018-03-07T15:28:51.0033534Z"}
NodaTime.Utility.InvalidNodaDataException: Unexpected token parsing Instant. Expected String, got Date.
   at NodaTime.Serialization.JsonNet.NodaPatternConverter`1.ReadJsonImpl(JsonReader reader, JsonSerializer serializer)
   at NodaTime.Serialization.JsonNet.NodaConverterBase`1.ReadJson(JsonReader reader, Type objectType, Object existingValue, JsonSerializer serializer)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.DeserializeConvertable(JsonConverter converter, JsonReader reader, Type objectType, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.SetPropertyValue(JsonProperty property, JsonConverter propertyConverter, JsonContainerContract containerContract, JsonProperty containerProperty, JsonReader reader, Object target)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.PopulateObject(Object newObject, JsonReader reader, JsonObjectContract contract, JsonProperty member, String id)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
   at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
   at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
   at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
   at UserQuery.Main() in C:\Users\<user>\AppData\Local\Temp\LINQPad5\_psvxrofa\query_xyushf.cs:line 44

The exception is slightly different than what my original test generated.

Versions in use:
Json.NET: 11.0.1
NodaTime: 2.2.4
NodaTime.Serialization.JsonNet: 2.0.0

[jskeet]

The problem there is that you're just adding the InstantConverter without disabling Json.NET's own Date handling.

If you call the ConfigureForNodaTime extension method instead, it should work - or you can do it yourself here:

jsonSettings.DateParseHandling = DateParseHandling.None;

If that's not the problem you saw in your production code though, we may still be a little way from it...

[thegreatco]

👍 That fixed it! Thanks @jskeet for such a fast response.

[jskeet]

Phew - glad it wasn't an actual bug :)